EU DataGRID testbed management and support at CERN

In this paper we report on the first two years of running the CERN testbed site for the EU DataGRID project. The site consists of about 120 dual-processor PCs distributed over several testbeds used for different purposes: software development, system integration, and application tests. Activities at the site included test productions of MonteCarlo data for LHC experiments, tutorials and demonstrations of GRID technologies, and support for individual users analysis. This paper focuses on node installation and configuration techniques, service management, user support in a gridified environment, and includes considerations on scalability and security issues and comparisons with "traditional" production systems, as seen from the administrator point of view.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX. PSN THCT00

Healthy younger and older adults control foot placement to avoid small obstacles during gait primarily by modulating step width

<p>Abstract</p> <p>Background</p> <p>Falls are a significant problem in the older population. Most falls occur during gait, which is primarily regulated by foot placement. Variability of foot placement has been associated with falls, but these associations are inconsistent and generally for smooth, level flooring. This study investigates the control of foot placement and the associated gait variability in younger and older men and women (N=7/group, total N=28) while walking at three different speeds (slow, preferred, and fast) across a control surface with no obstacles and surfaces with multiple (64) small (10cm long ×13mm high) visible and hidden obstacles.</p> <p>Results</p> <p>Minimum obstacle distance between the shoe and nearest obstacle during each footfall was greater on the visible obstacles surface for older subjects because some of them chose to actively avoid obstacles. This obstacle avoidance strategy was implemented primarily by modulating step width and to a lesser extent step length as indicated by linear regressions of step width and length variability on minimum obstacle distance. Mean gait speed, step length, step width, and step time did not significantly differ by subject group, flooring surface, or obstacle avoidance strategy.</p> <p>Conclusions</p> <p>Some healthy older subjects choose to actively avoid small obstacles that do not substantially perturb their gait by modulating step width and, to a lesser extent, step length. It is not clear if this obstacle avoidance strategy is appropriate and beneficial or overcautious and maladaptive, as it results in fewer obstacles encountered at a consequence of a less efficient gait pattern that has been shown to indicate increased fall risk. Further research is needed on the appropriateness of strategy selection when the environmental demands and/or task requirements have multiple possible completion strategies with conflicting objectives (i.e. perceived safety vs. efficiency).</p

Innovation in X-Ray technology

In the Non-Destructive Testing (NDT) industry, the mayor trends are from film and stand alone applications to digital and inline inspection. Furthermore the quality requirements are growing driven by pushing design and material limits. Especially for field applications based on security reasons as well as image quality, replacement of isotopes can be monitored. With the move to digital the need for small focal spots at increased power requirements brought new challenges to the x-ray supplier. With the move to inline inspection systems, requirements for high uptime, fast throughput at the best possible resolution became the key challenges for the x-ray industry. The target to replace isotopes brings high challenges for weight size and energy. The innovation program of COMET delivers solutions for those challenges. Comparison between 600 Kilovolts (kV) and conventional 450kV x-ray sources will show the advantages in penetration and resolution and with this in defect recognition. The resolution gain with adaptive focal spots compared to standard focal spots will be presented and the advantages of maintenance reduced high voltage cables will be shown

Selection, Drift, and Independent Contrasts: Defending the Methodological Foundations of the FIC

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2Fs13752-012-0070-2.Felsenstein’s method of independent contrasts (FIC) is one of the most widely used approaches to the study of correlated evolution. However, it is also quite controversial: numerous researchers have called various aspects of the method into question. Among these objections, there is one that, for two reasons, stands out from the rest: first, it is rather philosophical in nature; and second, it has received very little attention in the literature thus far. This objection concerns Sober’s charge that the FIC is methodologically flawed due to its (seemingly) resting on the assumption that the traits it studies evolved by drift—and thus ruling out selective hypotheses from the start. In this article, I try to rebut this charge. To do this, I first consider a preliminary conceptual worry—the question of how it is even possible for two drift-driven traits to be evolutionarily correlated—and show that it can be answered by noting that the FIC can be seen as being concerned with the investigation of the modularity of the relevant traits. Given this, I then show that Sober’s methodological charge can at least be mitigated by noting that the assumptions behind the FIC do not in fact preclude it from investigating selective hypotheses. I end by pointing out that making this clearer is not just relevant for defending the cogency of the FIC, but also for developing a deeper understanding of correlated evolution in general

Comprehensive Sleep Apnea Screening in Veterans with Posttraumatic Stress Disorder

Objectives: Recent studies have shown a higher prevalence of sleep apnea in veterans with Posttraumatic Stress Disorder (PTSD). It is estimated that 69 to 83% of veterans have Obstructive Sleep Apnea (OSA) while 80 to 90% are undiagnosed or untreated. Untreated OSA can lead to severe chronic medical conditions as well as impairment of neurocognitive and fear extinction processing potentially decreasing responsiveness to trauma focused therapy. Despite the widespread dissemination of knowledge regarding the negative effects of OSA, many veterans are not screened. The goal of this project is to increase the rate of identifying veterans who are high-risk for OSA. Methods: The Epworth Sleepiness Scale (ESS) and Berlin Questionnaire (BQ) were administered to veterans who presented for PTSD treatment over a two-month period. High-risk veterans were referred for a sleep study and treatment if diagnosed with OSA. Veterans with a prior diagnosis of OSA were screened to identify undertreatment. Results: Increase in identifying high-risk OSA from 5.5% to 71.4%, with an overall increase in the diagnostic rate from 22.2% to 78.3%. In veterans previously diagnosed with OSA, 90.1% were undertreated. Conclusions: Implementing a comprehensive screening process significantly improved the identification of veterans who are high-risk for OSA compared to usual practice. Identification and treatment of OSA is associated with an improvement in PTSD symptoms. Due to the potential effects of untreated OSA on psychiatric and medical conditions this screening process is applicable to both mental health and primary care settings

The English in the Levant: Commerce, Diplomacy, and the English Nation in the Ottoman Empire, 1672-1691

This dissertation examines the English who went to the Levant. Specifically, it analyzes the merchants, factors, ambassadors, chaplains, and embassy staff members who traveled to the Near East for either bureaucratic, commercial, or scholastic motivations. During their time abroad, these men amassed a wealth of knowledge and pecuniary resources, simultaneously furthering the countless interests forced upon them by the Levant Company and/or the English government. Thus, this dissertation asserts that the Ottoman Empire acted as a training ground for English emissaries, providing those who were abroad with the means of returning home to better positions of political, commercial, and/or diplomatic power. It further emphasizes that the Levant Company was yet another facet of the State, a formalized collective of mercantile agents acting on the behalf of the Stuart regime simultaneous to the mundane pursuit of trade

Integrated multi vector vortex beam generator

A novel method to generate and manipulate vector vortex beams in an integrated, ring resonator based geometry is proposed. We show numerically that a ring resonator, with an appropriate grating, addressed by a vertically displaced access waveguide emits a complex optical field. The emitted beam possesses a specific polarization topology, and consequently a transverse intensity profile and orbital angular momentum. We propose a combination of several concentric ring resonators, addressed with different bus guides, to generate arbitrary orbital angular momentum qudit states, which could potentially be used for classical and quantum communications. Finally, we demonstrate numerically that this device works as an orbital angular momentum sorter with an average cross-talk of -10 dB between different orbital angular momentum channels.Comment: 8 pages, 7 figure